The use of fluorescent taggants for value documents, value items, labels, ID cards, or other security purposes, is a well-developed field of invention, containing the work of many highly capable persons such as: William R. Rapoport, Judith D. Auslander, Gerhard Schwenk, Gary A. Ross, and Erich I. Rapaport.
Their patents most germaine to the background of the present invention will be outlined and discussed briefly.
U.S. Pat. No. 8,328,102 B2 by William R. Rapoport (the “Rapoport Patent”) uses taggants incorporated into or onto value documents, and contains methods of authenticating such documents by detecting and assessing emissions of radiation at pre-determined levels. The comparison process is done by a central processing unit (CPU), working with a programmable application specific integrated circuit (hereafter P-ASIC), so the emissions received from the value document are compared with pre-selected validation criteria to authenticate, or reject the value document.
The Rapoport Patent describes a first rare earth active ion in an inorganic crystal lattice, that absorbs incident infrared radiation with wavelengths from about 1300 nm (nanometers) to about 2200 nm. This energy is then transferred to a second rare earth active ion, which proceeds to emit a second wavelength that is longer than the first wavelength, i.e. from about 1400 nm to about 2200 nm. The authentication apparatus ascertains that the emission from the second active ion is within the pre-selected validation criteria.
So, what we have here is a chain, or sequence of linked occurrences, which could be called a cascade of excitation and emissions. The final result of this cascade depends entirely on the rare earth ions chosen, and the inorganic crystal lattices chosen. These variables produce emissions that are varied, depending on the choices made, and complicated enough to prevent counterfeiting.
The Rapoport patent seeks to vary and complicate the emissions so that unique validation criteria are created. A computer can store these, and use them to validate value documents at a later time. This system uses light emitting diodes (LED) as illumination sources and is intended to work at high speed on banknotes and other items.
What complicates the emissions in the Rapoport Patent is the cascade process, that entails using two rare earth ions in a sequence of excitations and emissions. There's a sequence of occurrences that takes place, and this results in an emissions signature that validates, or not, the banknote, or other item.
The amount (i.e. molar percent concentration) of the rare earth active ions can be varied as well, and this provides another dimension in which the material composition of the taggants zone can be varied.
If the variables: active ions, their concentrations, their substrate nanoparticles, and pairs of rare earths to make the sequences, must be changed for each banknote or other secured item, the Rapoport patent would be exceedingly difficult to make as a matter of manufacturing and precise emplacement of materials. It would be costly, and complex, or it would be not very reliable.
Even if the formulas are changed only once entire sets or series of secured items, it would still be costly and difficult to make value documents, or other secured items, in sets each of which had its own special combination of the materials that create variations in the final emissions profile that authenticates the members of the group. The patent would work, but it is overly complicated to make, and thus, commercially impractical.
On bank bills, particularly bank bills that, themselves, contained material of value, the Rapoport patent would be very attractive to would-be forgers since large sets of bank bills are authenticated by the same taggants zone mix, and emissions profile. The more intrinsically valuable the secured items, the more a forger can afford to spend breaking the security system and making counterfeits. If the bank bills contained gold metal, for example, the use of the Rapoport patent to protect them would be a magnet to forgers, and the larger the set of bills secured by the same taggants mix, the stronger the magnet. Making individual bills, each bill with its own special mix would be prohibitively costly, unreliable, and complex in high speed authentication.
The Rapoport patent is ideal for low value commodity products such as bottles of aspirin, which are made in large batches, and each batch could have its own taggants mix on the plastic seal over the bottle caps, or on the back of the containers. The cost of making new taggants zone mixtures would be amortized over many low-value units in the batch. No intrinsically valuable materials are involved, no gold, and no lives are at stake. The cost of changing the taggant zone mix must be low in the relation to the market value of the batch of commodity product. This means that the would-be forger has to spend a lot of money to break the security on a set of items that has a relatively low value. The Rapoport patent is ideal for deterring this sort of counterfeiting because it takes the profit out of the criminal act.
It would not work as well on gold bearing bank notes, or postal money orders, where the amounts of money intrinsic to the secured items, or in transit by means of the secured items, is very high, and would justify large a budget to be used for the purpose of beating the security system by making fake items that pass as authentic.
U.S. Pat. No. 7,926,730 B2 Combined Multi-Spectral Document Markings by Judith D. Auslander, et al., uses first and second sets of taggants, having different luminescence wavelength bands, such that, at an overlap location, they are not intrusive with each other. Together, they create a multi-spectral key, as drawn in FIG. 10 of the Auslander Patent. One of the spectral markings is prioritized, for authentication purposes, using information contained in the first marking. In a sense, one could say there's a key to the key. The priority data in the first marking triggers a pre-determined prioritization table, stored in working memory, which is then applied to the second marking. In short, the final key is by a sequence of occurrences that depend on the contents of the first and second taggants, which are in distinct taggant bearing areas on or in the value document, or value item.
As a practical matter, emplacing two taggants bearing zones that must be varied from item-to-item is costly, complex, and requires a level of authentication machine calibration that would be hard to maintain if the machine were operating at high speeds. To authenticate a document the two taggant zones must be used in sequence, since the first designates the pre-determined table used to validate the second. Just the physical process of mixing and emplacing the taggants zones for millions of different pieces of mail, would be very high compared to the marginal value to be gained by securely authenticating those mail items, or almost any items, except things of high value like bank bills containing gold, or money transfer orders, or things with sensitive security implications like ID cards, or evidence slabs or tags. The advantage of the system, using two taggant zones and many distinct prioritization tables, over regular bar codes, is not adequate to commercially support the complexity, emplacement of taggants costs, and operational fragility of the system. The system itself is ingenious, and if applied to large sets of interchangeable value items like containers of clothing, or bottles of medication, it would be viable and value-adding. However, linking the serially utilized spectral emissions to tables of priority comparison brought into working memory, would always be costly, complicated, and operationally fragile, to do at high speed. Such an authentication machine would be subject to frequent mis-cues, downtime, and outages.
U.S. Pat. No. 7,845,570B2 Value Document, a Patent by Gerhard Schwenk, et al., has at least three different feature substances, as ways of creating variations, to check a value document by one-to-one comparison. The second substance is luminescent, and the third substance is absorbent over a specific spectral range. By combining these, a spectral signature is produced, and then partially blocked. The third substance does not produce its own active luminescence, so it's hard for a would-be forger to analyze the third substance and know what it is. The third substance simply absorbs infra-red radiation, but it does not absorb radiation in the visible range. In the visible range no patterns or shapes can be seen. But in the IR range, patterns and shapes can be found, because of the use of the blocking material.
The substrate, which can be paper, made from cotton fibers, has the luminescent layer, and then the blocking layer is added by printing, gravure, screen, letterpress, inkjet, offset, or other similar method.
The emissions, from the resulting combination of layers, when examined in the IR range, form patterns or shapes, which can be varied, and thus create another axis of variation, on which the key, used to authenticate the document, can be applied. The authentication machine looks in the IR range for a signal in a specific shape or pattern, and uses two-dimensional pattern recognition to validate, or not, the document. One major advantage of the Schwenk Patent, is that soiling of the value document is not a problem in the IR range, which is what the authentication machine looks at. With soiling being much less of a problem, there is less need to remove noise from the signal (clean it up digitally in an optical spectrum analyzer). This feature of soiling over-coming, would be of significant value on bank notes, ID cards, or money orders, which can receive much soiling, due to much human handling.
In short, the Schwenk Patent combines luminescent taggants, and shaped IR blocking, to make patterns in two-dimensional space (on the plane of the document), and then, pattern recognition can be used to authenticate the document, in the IR range, where soiling is not a major problem.
If different patterns must be created, imprinted, and recorded for many secured items, this system is prohibitively expensive. If many items, in large sets, are imprinted and authenticated using the same patterns, the Schwenk Patent would work very well. This might be on labels for mass manufactured items like boxes of fasteners, or bottles of vitamins. This method would not be very secure, if the same pattern were used to identify many high-value items, like bank notes containing gold, or life-critical items such as ID cards or evidence slabs, where individual secure authentication is essential.
Since this method requires both spectral analysis and pattern recognition to validate an item, it is complex and difficult to run at high speed if all the items are differently coded. If they are valuable, or life-critical, and are all coded the same, the method of the Schwenk patent is inadequate as a security measure because the gain, to be obtained by breaking the code, is high enough to attract well-funded forgers of major talent, resources, and skill. The forgers would replicate the emissions and duplicate the patterns, in short order, if there were a huge financial or national security gain to be obtained by doing so. Any taggant system to be used on very sensitive items, or very valuable items, must withstand the dedicated efforts of the best and most skilled counterfeiters in the world, or it is a hazard, and not an enhancement.
U.S. Pat. No. 7,441,704 B2, System and Method for Identifying a Spatial Code, by Gary A. Ross, et al., describes a plurality of security tags having one or more characteristic emission spectral profiles that are detected by an image detector. The variations created, in this patent, depend on the shapes and position of the images, the spectral profiles, and decay times, because the security tags are stimulated by time-spaced illuminations. The spectrometer “sees” the emissions on a time-spaced basis.
For a secured item to be rated authentic, the spectral profiles, the spatial images, and the time-spaced emissions, must all be right
The “spatial image” of a spatial code includes one or many dimensional images of the code, at one or many emission wavelengths.
The received images, and time-spaced emissions are compared with pre-defined images and time-spaced emissions that are stored in a database. The emissions intensity, which decays over time, should last at least 100 nanoseconds to 10 microseconds.
The system described in the Ross Patent would be prohibitively costly if all the variables had to be changed to be applied on an item-by-item basis. The patent would be applicable to mark and authenticate objects in sets like aviation bolts, or parts of machines, or bottles of medication, which are mass manufactured, and yet their authenticity is important to persons in the supply chain, and to final users as well. This patent could apply to clothing containers, or retail goods.
The Ross Patent mentions LEDs to illuminate the tags and a CCD detector, and a spectrophotometer, to record the spatial codes and emissions spectra. The spatial code is identified, in combination with the spectral information, and that is how many variations are made. Marking sets of objects, in such a complex way, would be commercially feasible in large sets, but not for individual objects. The Ross Patent specifies that, for some applications, the exciting radiation and the emitted radiation are preferred to be in the visible range.
This patent would entail very complex calibration of the authenticating machine so that the CCD records, the spatial codes, the emissions profiles, and the decay time features, are all made part of the authentication process. A product, like bank bills, which runs into the millions of individual items, each of which needs its own authentication key, and which must be processed at high speeds, would not be commercially affordable, even if feasible, using the method described by the Ross Patent. When large amounts of money or human lives are at stake, and their loss cannot be insured against, such as CIA case officers, or Nuclear Regulatory Commission reactor inspectors, reliability, in the authentication of an ID Card, is crucial. The same applies to money orders, or evidence slabs, or tags. Reliable recognition of highly complex tags, using high speed equipment, would be uneconomic as a business proposition, even if the machines could be calibrated, because they would not perform smoothly for any significant amount of time. They would stop, and need to be adjusted often for satisfactory operational readiness, even if they could be made adequately reliable.
U.S. Pat. No. 5,986,550A by Erich I. Rapaport deals with nuclear resonance and electron spins which are authentication methods completely different from fluorescence and not in any way applicable to the present invention.
There have been numerous methods and apparatuses that use taggants to authenticate objects: (U.S. Pat. No. 20050178841 AlGuilford Jones, et al., System and Methods for Product and Document Authentication; U.S. Pat. 20100149531 A1 Shu Tuen Tang, Apparatus and Method for Object Authentication Using Taggant Material; U.S. Pat. 20060186348 A1 Brian Nguyen, et al., Method for Encoding Materials with a Luminescent Tag and Apparatus for Reading Same; U.S. Pat. 20080048106 A1 Elwood Neal Blanchard, et al., Method and Apparatus for Verifying the Authenticity of an Item by Detecting Encoded Luminescent Security Markers.)
Taggants have been used to verify objects by doping them on to nanoparticles in various ways: (U.S. Pat. No. WO 2011082031 A1 Brant U. Kolb, et al., Zirconia-based Particles Doped with a Lanthanide Element; U.S. Pat. 20030111644 A1 In-Gann Chen, et al., Process for Producing Nanoscale Yttrium Aluminum Garnet (YAG) Fluorescent Powders; U.S. Pat. No. 6,699,406 B2 Richard E. Riman and John Ballato, et al., Rare Earth Doped Host Materials; U.S. Pat. No. 20060033325 A1 Sriramakrishna Maruvada, et al., Authenticatable Article and Method of Authenticating; U.S. Pat. No. 20090224218 A1 George M. Williams, et al., Photoactive Taggant Materials Comprising Semiconductor Nanoparticles and Lanthanide Ions.)
Taggants have been used on or in plastic film, in strips, in layers, or in coats, and sometimes annealed to get better fluorescent intensity: (U.S. Pat. No. 20130040150 A1 Morgana M. Trexler, et al., Nanoparticle Taggants for Explosive Precursors; U.S. Pat. No. 6,699,406 B2 Richard E. Riman, et al., Rare Earth Doped Host Materials.)
Fluorescent taggants have been used to prevent forgery: (U.S. Pat. No. 6,663,960 B1 Toru Murakami, et al., Fluorescent Particles, Method for Preparing the Same and Paper Preventing Forgery Using the Fluorescent Particles.)
Mixtures of taggants have been used to produce random patterns of spectrally varying fluorescence to make a unique signature for each label, and where the fluorescence signature for each label is entered into a database at the point of manufacture or point of application: (U.S. Pat. No. 6,692,031 B2 Stephen P. McGrew, Quantum Dot Security Device and Method.)
Tamper-evident security coatings, labels, films, or plastic layers can be affixed to a product so that fragmentation occurs to disclose any tampering: (U.S. Pat. No. 5,411,295 A Scott B. Bates, et al., Tamper-evident Label; U.S. Pat. No. 6,447,015 B1, Ron Linnewiel, Tamper-Evident Tapes and Labels; U.S. Pat. No. 6,096,387 A Thomas A. Decker, Methods for Providing Self-Adhesive Resealable Tamper-Evident Tape.)
Infra-red radiation has been used with taggants doped with two rare earth ions to authenticate value documents: (U.S. Pat. No. 20110147450 A1 William Ross Rapoport, et al., Method and Authentication for Authenticating Value Documents.)
The present invention overcomes the limitations of the prior art, by using Digital Signal Processing (DSP) inside the authentication machine, instead of complex patterns, shapes, emission decay times, blocking, or cascades of emission and re-emission on the value item. The present invention is a method of authenticating a value item that relies partially on fluorescent taggants. But mainly, it relies on digital signal processing (DSP), that takes place on Programmable Application Specific Integrated Circuit chips, herein called P-ASIC chips, and in a computer.
Every aspect of the authentication process, leading up to the full-wide spectral peaks profile coming to the optical digital spectrum analyzer can be called the “front-end” of the authentication system. This includes light emitting diode (LED) illumination of the taggants, capture by the sensors, of the resulting fluorescent emissions from the taggants, and devices to digitize and preliminarily clean up the signal, by elimination of electronic “noise”.
The Digital Signal Processing (DSP) claims of the present invention are focused on the programmable finite impulse response (FIR) filter. FIR filters have been on the market for a long time. This invention pertains to their application in making multiple passbands (snippets) for purposes of authenticating a value document or item.
The invention uses DSP to allow a single standardized uniform set of taggants to authenticate a whole series containing millions of value documents or items.
Many patents have been written that seek to create variations of a spectral peaks signature. They do it in ways that can be broken down into classes. These are presented in the Background section of this specification. The present invention relies on one variation of the taggants for an entire series of value documents or items, and thus it is cheaper, better, faster, and more secure, than any of the ways described in the prior art. The field, of using taggants to identify items, is long-standing, and crowded with innovations, so the background patents are ingenious, but too costly and complex, to be entirely practical for commercial purposes.
The present invention departs from the others, because it uses just one taggants group, per series of value documents or items, to authenticate possibly millions of items. This is done by using a Finite Impulse Transform (hereafter FIT) algorithm in conjunction with a Programmable Finite Impulse Response filter (hereafter FIR or “brick wall”). The FIR filter makes snippets, which can be highly various, but are all based on the same full-wide emissions coming from the standardized and uniform Taggants Zone used on that series of value documents or items.
Nothing, on the secured value documents or items, is sufficient to generate a false rating of “authentic”, no matter how skillfully the secured items are reverse-engineered and physically replicated. A perfectly copied taggants zone won't be enough. Even if the taggants zone is perfectly copied, and even if the file number, which is highly encrypted, is somehow decrypted, or just copied without decrypting it, the forger can only counterfeit one of the secured items. Crimes that are very difficult, risky, and costly to do, and yield almost nothing, by comparison to the cost of doing them, are not done. In the case on an ID Card, or evidence slab, or tag, there are secondary human back-ups in the form of trained, observant, security professionals, which the forger would not be able to overcome. ID Cards can include: color photographs, biometric data, holograms, and other elements or methods.
The present invention has the unique feature that any secured item can be invalidated at any time by re-programming the programmable FIT algorithm and FIR filter files on the P-ASIC chips in the computer. Software can be updated, and all the data on the P-ASIC chips is software. Every file in every library of variables, or of final verification keys, can be erased and replaced. The chips themselves can be removed and replaced with chips that contain entirely different variables files for making snippets, and as comparison keys in a database, for final one-to-one comparison for getting a rating of “authentic”.
The present method is robust. It can take a hit. If it's being beaten by a forger, or if one of the authentication machines is captured by criminals and the P-ASIC chips read out, this system can be updated and restored to full security readiness with changes in software, changes in P-ASIC chips, or, in a worst case, by incapacitating and replacing all the P-ASIC chips in the system.
The ability to respond quickly and decisively to a major security breach is something no other patent in this field has.
Soiling can put noise into the system, and make it hard to clean up the signal in the optical digital spectrum analyzer. But, the system, of the present invention, can achieve the same result by simply giving the sensors and the optical spectrum analyzer more time on each item.
More time under examination means better resolution. Thus, this system is robustly able to respond of soiling challenges. None of the background patents have any commercially significant advantages over system of the present invention in the soiling mitigation area of performance.
The Taggants Zones, on all the value items of a given set, from a given organization, are all identical. The taggants are placed on or in the substrate, which may be paper, or plastic, in a way, which may include, but not be limited to: in straight stripes, in wavy stripes, in circles with the widths the same, (like an archery target), in circles with the widths not the same, in polygons such as rectangles, parallelograms, and hexagons, or in layers.
The taggants chosen must, when illuminated by an array of LEDs, emit fluorescence over a full-wide range. This means a lot of emissions, at high intensities, in the range from 200 nanometers to 1500 nanometers. This requires selecting rare earth ions, nanoparticles, and concentrations (molar percentages), that, when used as a group, will create many intensive emissions peaks over the fullest and widest range practicable within the specification 200 to 1500 nanometers.
Since the taggants zones are all standardized and uniform over the full range of value documents or items in a series, it is cheap to put them on the set of items by: printing, gravure, inkjet, screen, etc. There are no special shapes, or special blocking patterns hidden in the taggants zones of individual items. There are no special decay times, or electron spins, or nuclear resonance factors, that vary from item-to-item within the set. Millions of secured items can be given the standardized uniform taggants zone which can be emplaced on them using a low-cost way. This is one aspect of the present invention, that represents a major departure from what was known before. The method of the present invention is commercially viable because it is cost-effective to emplace the taggants on or in the value items, because in a given set, all the taggants zones are standardized, uniform, and simple to print. This greatly enhances reliability, as well keeping costs down.
The taggants zone, in its specific combination of rare earth ions, nanoparticles, and concentrations, by itself, is only marginally relevant to the authentication process. It is physically necessary, by functionally insufficient, to ever generate an authentication. This invention is centered on the variables sets, on the Programmable Application Specific Integrated Circuit, or P-ASIC, chips in the computer from which the FIR filter makes the snippets. The snippets are the true criteria to authenticate individual secured items.